This invention pertains to the art of shutoff valves and more particularly to bellows valves.
The invention is particularly applicable to an inverted bellows valve assembly and will be described with particular reference thereto. However, it will be appreciated that the invention has broader implications and may be advantageously employed in other valve environments and applications.
Bellows valves are commonly employed in environments where sealing and cleanliness are of utmost importance. For example, bellows valves are used in the chemical industry to shut off flow of various system fluids and the like. Because of the caustic nature of many of these fluids, a more reliable sealing relationship between wetted components of the valve is always desirable.
In other industries such as the semiconductor industry, it is desirable that the surrounding environment remain as free of contaminants as possible to prevent introduction of imperfections into the final product. In the past, a suitable lubricant was necessarily placed between cooperating threaded components. The lubricant, although a requisite for valve assembly, can be considered a contaminant in such closely monitored applications as the semiconductor industry. Therefore, reduction and/or elimination of the lubricant is highly desirable from the standpoint of cleanliness.
The subject invention provides a new and improved inverted bellows valve construction which is deemed to meet the foregoing needs and solve the above-described problems and shortcomings associated with prior valve designs.